Fixes issue with the search input box always taking the user to default language page

[cjyabraham]

Fixes issue with the search input box always taking the user to the default language search results (https://github.com/google/docsy/issues/1558)

The problem was that the js script had no knowledge of the current language and so always redirected the user to the default language page. Here I'm passing the correct search results page in to the script from a data element on the search input box.

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[chalin]

Thanks for this PR @cjyabraham. FYI, this is still on the radar. I'll add it as a candidate to release 0.11.0 (#1944). Docsy 0.10.0 is just hot off the press! 🔥